Ca silicate phase separation

 Coarse grain aluminum thermal process via high endothermic reaction in the WC tungsten produced directly from the method can produce high-purity, coarse, large, single-phase WC grains.

8 molten tungsten carbide method (gas injection method) First, a high temperature at 1050-1100 ℃, using tungsten Na2SiO3-NaCl molten salt will decompose the generated Na2WO4-NaCl same molten salt containing Fe, Mn , Ca silicate phase separation, and then injected into the molten phase with methane to generate coarse grain WC. Advantages of the method of low cost, typically about 60%, the disadvantage of impurities (Mo, Cr, Fe, Ni, Si) content is high, chemical treatment takes a long time.Coarse-grained tungsten carbide formula WC, has some Molybdenum crucible and fine grained WC powder different special properties and uses, especially high temperature WC with fewer structural defects, high hardness and micro strain etc, widely used in mining ground, oil drilling, lathe and so on. Hardness only to diamond, high value. Currently coarse grained WC production methods are:

1 high temperature carbonization tungsten powder long carbonation, lattice defects can make the WC minimize the smallest micro-strain, WC plasticity improved. This is currently the main mode of production. Carbonization temperature should not exceed 1800-1900 ℃, in more than 1800 ℃, WC grain boundaries between the grains prone fusion grew, resulting in uneven distribution of WC grain size. Some studies show that reducing particle size of the tungsten material, increased carbonization temperature, carbonization time reduction, the quality can be improved to obtain a WC.